Various thin film layers for semiconductor devices may be deposited with atomic layer deposition (ALD), chemical vapor deposition (CVD), or plasma-enhanced chemical vapor deposition (PECVD) processes. Under some conditions, some ALD processes may be unable to saturate the substrate, leading to incomplete film deposition on the substrate, film islanding, and film thickness variation. Similarly, under some conditions, some CVD and PECVD processes may be mass transport limited, and may be unable to cover high-aspect ratio device structures.
Some approaches to address incomplete film deposition may include, in ALD processes, longer dosing times to saturate the substrate surface with film precursor, and in CVD and PECVD processes, lower pressures to enhance mass transfer efficiency. However, extending dosing times and/or operating at lower pressures may diminish process tool throughput, requiring the installation and maintenance of additional process tools to support a production line. Further, films produced by such approaches may have physical, chemical, or electrical characteristics that provide inadequate device performance.